Q:
I play badminton two or three times a week. In a recent game I felt and heard a pop in the top rear muscle of my left leg, just under my buttock. It can be painful, especially at night. Will it repair itself soon so I can play again?
A:
What you’ve described is a hamstring injury, a tear involving the tendons or large muscles at the back of the thigh. The hamstrings are actually a group of three muscles — they essentially allow you to bend your knee — while the tendons attach these muscles to the bones of the knee and the top of the thigh bone.
A sudden movement can cause a tear, which is acutely painful. The popping sensation you noticed may be a sign it was a fairly severe injury: the ‘pop’ is caused by the sudden snapping of a tendon (rather than the pulling apart of the muscle). If the tendon has torn completely it would make it difficult to walk or fully extend your knee and it can take time to heal — it may be several months before you can resume active exercise such as badminton. In the meantime, gentle exercise such as walking is sensible but you must let pain be your guide in terms of how much you do.
However, the increase in pain at night raises a question. Could it be that you have actually torn off one of the three muscles that make up the hamstrings from where it joins the bones in the pelvis? Night pain is one sign of this and you may need an ultrasound scan or an MRI to confirm it. I’d strongly recommend discussing it with your GP.
More detailed information from Florida MD: